Let's say the remarkable concept of infinite parallel universes has been proven to be true, and humans have constructed a device that can send you to another version of Earth for 36 hours. One of the interesting aspects of this device, though, is that you can "dial back" to any point of divergence you want.

Warning - Crazy Explanation:Infinite universes really does mean INFINITE. There is another universe for every possible combination of atoms. So there are universes nearly identical to ours and those that are vastly different.

The device mentioned above allows you to choose how far back your destination world diverged from our own. Let's say you choose to visit a world that diverged from ours ten minutes ago. This means the world was identical to ours in every way up until ten minutes ago. But for the last ten minutes, events on that world have been independent of our world. Not much can happen in ten minutes, so that world would be very similar to ours, including all the people (except for those who died in that ten minutes on one world but not on the other).If you choose a world that diverged ten years ago, it would still be similar. But a lot can happen in ten years. Elections could have resulted in different leaders, for example, resulting in somewhat different social landscapes.

What about a world that diverged 100 years ago? None of the same people would exist, except those who are more than 100 years old.

What about 1,000 years ago? That world could look quite different, right? Different languages, different political boundaries. Maybe even the extinction of life on Earth due to imprudent use of nuclear weapons.

What about a world that diverged 10,000 years ago? Or 100,000? or 100 million?

Boggles the mind, doesn't it?

Keep in mind this isn't time travel. If you leave this world on December 12, it will be December 12 on the alternate version of Earth you visit. But you get to choose how far back the world diverged from ours.

So here is a question for you:If you had the opportunity to visit an alternate version of Earth, how far back would you want the divergence point?